Lead levels in Eurasian otters decline with time and reveal interactions between sources, prevailing weather, and stream chemistry

The uptake of contaminants by biota varies spatially and temporally due to a complex range of interacting environmental variables, but such complexities are typically disregarded in studies of temporal change. Here, we use linear modeling to explore spatial and temporal variation in bone Pb levels measured in samples taken from 329 Eurasian otters (Lutra lutra) found dead in southwest England. Between 1992 and 2004 Pb levels in otters fell by 73%, following UK legislative control of Pb emissions implemented since the mid 1980s. Spatial variation in bone Pb was positively correlated with modeled Pb emissions and stream sediment Pb, which interacted negatively with wind-speed and sediment Ca, respectively. Opportunistic collection of samples from wildlife mortalities provided a valuable opportunity for monitoring environmental contamination, interpretation of which was aided by spatially explicit analysis of environmental variables.     

室内环境设计与装饰装修

通过对室内环境设计与装饰装修自身特点以及前存在问题的剖析。提出了室内环境设计与装饰装修的三条基本原则：以“人”为中心的原则；以“文化”为基调的原则以及与各相关系统相统一的原则。     

房产交易与信息发布系统的开发及实现

综合考虑了一般房产管理的运行模式和现有的网络地理信息系统实现方法,在探索一个性能价格比高的房产交易与信息发布系统的实现方法的基础上,提出了一种基于Internet或Intranet上的房产交易管理信息系统模型模式;采用网络的主流技术ASP,同时结合ESRI公司的ArcIMS用SQLSERVER2000数据库实现房产交易管理和房产信息发布。     

OptaDOS: A tool for obtaining density of states,core-level and optical spectra from electronic structure codes

We present OptaDOS, a program for calculating core-electron and low-loss electron energy loss spectra (EELS) and optical spectra along with total-, projected- and joint-density of electronic states (DOS) from single-particle eigenenergies and dipole transition coefficients. Energy-loss spectroscopy is an important tool for probing bonding within a material. Interpreting these spectra can be aided by first principles calculations. The spectra are generated from the eigenenergies through integration over the Brillouin zone. An important feature of this code is that this integration is performed using a choice of adaptive or linear extrapolation broadening methods which we show produces higher accuracy spectra than standard fixed-width Gaussian broadening. OptaDOS  may be straightforwardly interfaced to any electronic structure code. OptaDOS  is freely available under the GNU General Public licence from http://www.optados.org.     

A simple computational model for analyzing the properties of stop-loss,take-profit,and price breakout trading strategies

Stop-loss, take profit and price breakout strategies, though in some ways theoretically unattractive, are nonetheless popular with traders. We describe and illustrate a simple, fast, flexible and practical discrete time computational model for performing probabilistic analyses of the risks, rewards and tradeoffs associated such strategies.     

酶箱模具设计和改讲

通过对酶箱模具设计和改进过程的分析,提出了企业在追求低投入高产出时,必须是在确保产品质量的前提下考虑效益最大化,否则是得不偿失的。提示设计人员在搞设计时,要把握住质量和投入的平衡。     

Solitary rectal ulcer syndrome

BACKGROUND: Solitary rectal ulcer syndrome is a rare disorder characterized by erythema or ulceration of the rectal wall, associated with typical histological features, and disturbed defaecatory behaviour with the passage of blood and mucus. METHODS: This is a review based on a literature search using a computer database (Medline) and manual cross-referencing. RESULTS: The pathogenesis is likely to vary in different patients; it includes trauma from straining, direct digital trauma and possibly primary neuromuscular pathology. The histological findings of extension of the muscularis mucosa between crypts and muscularis propria disorganization on full-thickness specimens are characteristic. Biofeedback defaecation retraining, including habit training, can lead to symptom improvement and return to work in a majority of patients. Abdominal rectopexy offers long-term symptom improvement in approximately 50 per cent of patients. Rectal ulceration may persist after any treatment, even if symptoms improve. CONCLUSION: Behavioural therapy and carefully considered operations offer the best treatment results. Further work on psychological factors and neuromuscular and vascular pathology is required.     

Fine structure and development of dorsal root ganglion neurons and Schwann cells in the newborn opossum Monodelphis domestica

The aim of these experiments was to determine the state of maturity of dorsal root ganglia and axons in opossums (Monodelphis domestica) at birth and to assess quantitatively changes that occur in early life. Counts made of dorsal root ganglion cells at cervical levels showed that the numbers were similar in newborn and adult animals, approximately 1,600 per ganglion. In cervical dorsal root ganglia of newborn animals, division of neuronal precursors cells had ceased. The number of axons in cervical dorsal roots was similar in newborn and adult animals (about 4,500). For each ganglion cell body, approximately three axons were counted in the dorsal root. At birth, dorsal roots contained several bundles about 30 microns in diameter consisting of small axons (0.05-2 microns in diameter). A few non-neural cells were identified as Schwann cell perikarya, each enclosing a number of neurites. Later, marked changes occurred in Schwann cells and in their relationship to axons in the roots. Thus, at 12 days, an increase occurred in the number of Schwann cells and fibroblasts, and the bundles had enlarged to about 80 microns with little increase in axon diameter (0.1-2 microns). By 18 days, the bundles were larger, and myelination had already started. At 23 days, the dorsal root contained more than 500 myelinated axons that could reach 5 microns in diameter. The adult dorsal root enclosed about 900 myelinated axons. Throughout this time, the relationship between the Schwann cells and axons changed. Together, these results indicate that the number of axons and cell bodies of sensory dorsal root ganglia in opossum do not show major changes after birth. In addition, these results set the stage for quantitative studies of regeneration of dorsal column fibers in injured neonatal opossum nervous system.     

Nitric oxide inhibition in an ovine model of heart failure

1. The role of nitric oxide (NO) in congestive heart failure was investigated by studying the acute haemodynamic, hormonal and renal effects of N(G)-monomethyl-L-arginine (L-NMMA(, a nitric oxide inhibitor, given as incremental bolus doses in six sheep before (normal) and after induction of heart failure (HF) by rapid left ventricular pacing (LVoff+). 2. 6-NMMA caused significant initial dose-dependent rises in left ventricular systolic pressure, mean arterial pressure (MAP), peripheral resistance (PR) and left atrial pressure and declines in cardiac output in both normal and HF states (maximum response in 2-6 min). These responses were all but abolished when L-arginine was given concurrently with L-NMMA. The dose-response curve for the L-NMMA-induced rise in MAP was shifted to the right following LVP (P < 0.05), which is consistent with previous observations of blunted NO synthase activity in HF. A subsequent decline in MAP and PR to below prebolus levels was observed 30-60 min after L-NMMA administration in the paced state. No significant hormonal or renal effects were observed. 3. In conclusion, the present study confirms the important haemodynamic role played by endogenous NO in the normal state and demonstrates a blunted pressor response to NO inhibition in this model of heart failure.